The present application relates to throttle bodies for intake manifolds of a spark ignition internal combustion engine. More specifically, the present invention relates to an intake manifold for a spark ignition internal combustion engine that has an integrally molded plate, shaft and lever assembly.
In the past, there has been a need for easy to assemble, lightweight and more reasonably priced components for fuel injected engines which require a throttle body. In the past, throttle bodies have typically been configured as a one-piece housing in which a plate, shaft and lever assembly were assembled in separate pieces of a housing. Typically, because of the one-piece construction of the housing, a somewhat time consuming assembly process was necessary in order to pivotally secure the plate member inside of the throttle body bore and thereafter connect the peripheral portions and/or control inputs along the shaft.
Thus, in typical prior art constructions, a multi-step process was required for pressing bearings and then installing the shaft, springs, and lever assembly and the like. Typically with such constructions, the throttle control spring was inboard of the throttle lever assembly. Additionally, the throttle lever assembly, shaft and plate were all separate pieces which needed to be connected by way of rivets or the like in order to provide a finished throttle body for installation on an engine. As might be readily appreciated, most of these parts have been made from metal, which is heavy, and the steps necessary to assembly the throttle body made such units relatively expensive components of the vehicle engine.
In recent years, there have been some advances in throttle body designs, such as providing a two-piece assembly. A two-piece throttle body makes it easier to install the plate member. However, there remains a need for making an inexpensive yet reliable throttle body housing.
In accordance with the present invention, there is provided a throttle body assembly for an engine, which includes a throttle body housing having a central intake bore therethrough. In the present invention, a throttle plate member is rotatably disposed in said bore for metering air flow through the throttle body and to the engine. The throttle plate member of the present invention includes a shaft member, which is effective for pivoting the plate member about an axis. In the present invention, the throttle plate member and the shaft and lever assembly and the like are integrally formed by one-piece injection molding and installed in the throttle body as a single piece.
Further understanding of the present invention will be had by reference to the detailed description of the preferred embodiments set forth below when taken in conjunction with the examples and claims appended hereto.